Generally, the outsides of windows fixed to buildings are apt to become unclean and are difficult to clean. In order to eliminate the difficulty in cleaning the outside of a window, a window which permits easy cleaning of the outside thereof is conventionally known, which is constructed so as to be completely turned inside out, so that, when cleaning is necessary, its outside is directed to the inner side and its outside can be cleaned without difficulty from the inside of the room. In many of the windows of such a type, a rotary shaft is disposed in the center of the frame of the window, and the window can be rotated about the rotary shaft. However, in such windows, the area of the window that can be completely opened is half of a full size of the window at the most, and if the window is a small, such opened area will not serve as an emergency exit or a fire exit. In order to eliminate the shortcoming of the conventional reversible window, there can be proposed a window in which the rotary shaft is shifted from the center of the window frame to one side thereof. In this case, however, complete inside-out rotation of the window is not attained, so that complete cleaning of the outside of the window from the inner side is difficult.
Under such circumstances, there has been previously developed a reversible window having a movable rotary shaft as shown in FIG. 1. In the figure, reference numeral 1 represents a window; reference numeral 2, a rotary shaft; reference numeral 3, a guide projection; reference numeral 4, sash rollers; reference numerals 5 and 6, pinion gears; reference numerals 7 and 8, rack gears; reference numeral 9, a guide rail; and reference numeral 10, an arm member. The window 1 can be rotated about the rotary shaft 2. During the rotation of the window 1, the rotary shaft 2 is moved along the upper rack gear 7 and the lower rack gear 8 under the guidance of the upper pinion gear 5 and the lower pinion gear 6 which respectively engage the upper rack gear 7 and the lower rack gear 8. The movement of the rotary shaft 2 is also regulated by the arm member 10 as shown in FIG. 1. One end of the arm 10 is rotatably fixed to a reverse rotation shaft 17 fixed to the center of the upper window frame of the window 1 and the other end of the arm member 10 is rotatably fixed to one end portion of an outer frame 11 of the window 1 (refer to FIG. 2).
Referring to FIG. 2 and FIG. 3, the reversing of the window 1 will now be explained. Referring to FIG. 2, the window 1 is opened from its initial position, while the rotary shaft 2 engages the pinion gears 5 and 6 and the rack gears 7 and 8. When the window 1 comes to a position II via a position I, the window 1 is positioned at a right angle with respect to the initial position thereof as shown in FIG. 2. With further rotation, the window 1 is reversed and comes to a position III and finally to a position as shown in FIG. 3, where the window 1 is fitted in the initial position, but it is completely turned inside out with a 180-degree reverse rotation.
When the window 1 is at the position II, the window 1 cannot be moved up to the extreme end of the outer frame 11 due to the limitation of the length of the arm 10, and the window 1 is at a distance a from the extreme end of the outer frame as shown in FIG. 2.
Therefore, the maximum effective open width of the window at the position II with a 90-degree opening is W-a, where W is the entire width of the window 1. As a matter of course, if the window is used as an emergency exit and the maximum effective open width must be W, the outer frame must be designed so as to be greater than the width of the window by the size a.
In the above-described reversible window, the reverse rotation shaft 17 is secured to the center of the window frame of the window 1. In contrast to this, when the reverse rotation shaft 17 is shifted from the center of the window frame towards the fixing position of the arm member 10 on the side of the outer frame 11 of the window 1 as shown in FIG. 4(a), the window 1 can be moved up to the extreme end of the outer frame 11 when the window 1 is at the 90-degree opening position as shown in FIG. 4(b). However, further rotation of the window 1 for a 180-degree reverse rotation is impossible since the lower end of the window 1 is caught by the extreme end portion of the outer frame 11 and cannot be moved any further.
On the other hand, when the reverse rotation shaft 17 is shifted beyond the center of the window to the right, as shown in FIG. 5(a), using a longer arm member 10, the window 1 cannot be moved to the extreme end of the outer frame 11 when the window 1 is at the 90-degree opening position as shown in FIG. 5(b), and it cannot be fitted into the initial closing position even if 180-degree reversing is tried as shown in FIG. 5(c), since the right end portion of the window 1 comes beyond the right side of the outer frame 11 of the window 1.
The present invention is an improvement on the above-described shortcomings, by which improvement the complete 180-degree reversing of the window can be attained wherever the reverse rotation shaft 17 is positioned, and at the time of the 90-degree opening, the window can be moved up to the extreme end of its outer frame.